The invention relates generally to portable devices which can be readily attached (and removed) for securely holding a door closed. This would likely be used in addition to conventional locks and bolts which are an integral part of the door, door frame and jamb construction.
My earlier U.S. Pat. No. 4,022,503 dated May 10, 1977, describes a chain type of portable door securing device. Briefly, this earlier device has a thin strong member which hooks onto an edge at the opening of the striker plate located in the door jamb and extends along the door jamb and has a chain at its other end. When the door is closed the chain is wrapped around or attached in some fashion to the door knob. This type of device has some flaws which are overcome by the present device.
Other types of door security devices of a portable nature which have an elongated member which hooks into the opening in the striker plate and utilize a cylindrical member for threadably engaging the elongated member and pressing against the door and door jamb to hold the door closed are shown in the following U.S. Pat. Nos: 894,554; 898,685; 1,188,699; 1,434,411; 3,429,151; 3,494,653. Although all of these security devices work generally on the same principle, each are lacking in some material aspect which the instant invention overcomes.